PHILADELPHIA (CBS) — The Philadelphia School District is scheduled to unveil its 2015 “lump sum budget,” at Thursday night’s School Reform Commission meeting, and it’s expected to be another bare bones spending plan. The district’s budget crunch prompted a number of calls for action, including a tax on Marcellus shale gas.

Standing outside school district headquarters, State Senator Vincent Hughes announced plans to introduce a bill that would place a five percent tax on natural gas extracted from Pennsylvania to be used, in part, for public schools.

“Pa is the only state in the nation where there is no severance tax on shale drilling. No more passes. Everybody’s got to pay their fair share because the people who suffer when the very wealthy get away clean are our children,” Senator Hughes said.

Hughes was joined by colleagues, parents, teachers and students, including Angel Martinez.

“It is not fair that students have to be in schools that don’t have what they need. Some schools don’t have enough books or supplies for everyone so how are we supposed to learn?” Martinez said.

Hughes estimated the tax could raise more than $700 million dollars in the next year, with half going to schools.